- Osimertinib yielded good objective response rates (ORRs), with promising PFS, in previously treated epidermal growth factor receptor-mutated (EGFRm) NSCLC and leptomeningeal metastases (LMs).
Why this matters
- There are currently no standardized therapies for EGFRm NSCLC with LMs.
- Open-label, multicenter, phase 1 trial.
- 41 patients with EGFR-mutated NSCLC and LMs previously treated with EGFR tyrosine kinase inhibitors received 160 mg osimertinib once daily.
- Median follow-up, 9.9 months.
- Funding: AstraZeneca.
- Clinically meaningful LM ORR was recorded, but the ORR was higher by neuroradiologic-blinded central independent review (BICR) than by investigator (62% vs 27%).
- Stable disease rate was also clinically relevant, but differed by reviewers (61% by investigator vs 32% by BICR).
- Median LM duration of response was 15.2 months by BICR and 18.9 months by investigator.
- Neurological function improved in 57% of patients with abnormal neurologic function at baseline.
- Median investigator-assessed PFS was 8.6 months, with 42% of patients progression free at 12 months.
- Tolerability profile was similar to that in previous studies of osimertinib.
- 66% of patients had grade ≥3 AEs.
- Discrepancies in BICR and investigator results.